A brief and critical review on hydrofluorosis in diverse species of domestic animals in India.

India is one of the fluoride-endemic countries where the maximum numbers of ground or drinking water sources are naturally fluoridated. In India, a total of 23, out of 36 states and union territories have drinking water contaminated with fluoride in varying concentration. In the present scenario, especially in rural India, besides the surface waters (perennial ponds, dams, rivers, etc.), bore wells and hand pumps are the principal drinking water sources for domestic animals such as cattle (Bos taurus), water buffaloes (Bubalus bubalis), sheep (Ovis aries), goats (Capra hircus), horses (Equus caballus), donkeys (Equus asinus) and dromedary camels (Camelus dromedarius). Out of 23 states, 17 states, namely Andhra Pradesh, Assam, Bihar, Chhattisgarh, Gujarat, Haryana, Jharkhand, Karnataka, Kerala, Madhya Pradesh, Maharashtra, Odisha (Orissa), Punjab, Rajasthan, Telangana, Uttar Pradesh and West Bengal, have fluoride beyond the maximum permissible limit of 1.0 or 1.5 ppm in drinking water. This situation is a great concern for the animal health because fluoride is a slow toxicant and causes chronic diverse serious health hazards or toxic effects. Despite the fact that domestic animals are the basic income sources in rural areas and possess a significant contributory role not only in the agriculture sector but also in the strengthening of economy as well as in sustainable development of the country, research work on chronic fluoride intoxication (hydrofluorosis) due to drinking of fluoridated water in domestic animals rearing in various fluoride-endemic states is not enough as compared to work done in humans. However, some interesting and excellent research works conducted on different aspects of hydrofluorosis in domesticated animals rearing in different states are briefly and critically reviewed in the present communication. Author believes that this review paper not only will be more useful for researchers to do some more advance research work on fluoride-induced toxicosis in different species of animals but will also be helpful in the making of health policy for domestic animals at state and national level for the mitigation of hydrofluorosis in India.

Water Quality for Cattle: Metalloid and Metal Contamination of Water.

Water is the most important nutrient for rangeland livestock. However, competition with municipalities, industry, and other water users often results in grazing livestock being forced to use water supplies that are less than perfect. Surface water in western rangleands are often contaminated by mineral extraction, irrigation runoff and other human activities. Mineral contaminants in drinking water are additive with similar contaminants in feedstuffs. The goal of this article is to provide producers and veterinarians with the basic background to make informed decisions about whether a given water supply is "safe" for livestock.

Fluorosis as a probable cause of chronic lameness in free ranging eastern grey kangaroos (Macropus giganteus).

A population of eastern grey kangaroos (Macropus giganteus) inhabiting heathland and farmland surrounding an aluminum smelter at Portland, Victoria, Australia, exhibited clinical signs of lameness. An investigation was undertaken to determine the cause of this lameness. Hematology, necropsy, histopathology, fecal egg count, total worm count, reproductive status, and the population age range were examined and failed to reveal any additional underlying disease state. The specific problem of lameness was addressed with bone histopathology, radiography, quantitative ultrasonography, microradiography, and multielement analysis of bone ash samples. The significant lesions observed were: osteophytosis of the distal tibia and fibula, tarsal bones, metatarsus IV, and proximal coccygeal vertebrae; osteopenia of the femur, tibia, and metatarsus IV; incisor enamel hypoplasia; stained, uneven, and abnormal teeth wear; abnormal bone matrix mineralization and mottling; increased bone density; and elevated bone fluoride levels. Microradiography of affected kangaroos exhibited "black osteons," which are a known manifestation of fluorosis. Collectively, these lesions were consistent with a diagnosis of fluorosis.

Skeletal Pathology of Eastern Grey Kangaroos (Macropus giganteus) Exposed to High Environmental Fluoride Levels in South-Eastern Australia.

Significantly elevated bone fluoride concentrations have been reported in a population of eastern grey kangaroos (Macropus giganteus) resident near a fluoride-emitting aluminum smelter in southeastern Australia. This paper describes the skeletal and synovial joint lesions observed post mortem in the same sample of kangaroos (n = 76). The prevalence and severity of skeletal lesions, specifically the formation of multiple, large, smooth exostoses over the diaphysis of long bones (especially, but not exclusively, on the tibia, fibula and metatarsi), were positively associated with bone fluoride concentration. So too were lesions of degenerative joint disease, including periarticular osteophytosis, articular cartilage erosion/ulceration, synovial hyperplasia and joint capsular fibrosis. Joint lesions were most commonly seen in the knee, hock and metatarsophalangeal joints. This is the first study to describe in detail the full range of lesions induced by chronic fluorosis in a marsupial species.

Cytogenic investigations on leucocytes of cattle intoxicated with fluoride.

Cattle which grazed in the vicinity of a plant manufacturing enamel and which displayed signs of chronic fluoride poisoning such as osteosclerosis and mottled enamel or dental fluorosis were investigated for the presence of structural chromatid and chromosome aberrations. Venous blood was incubated for 48 h, and 100 cells were analyzed for each animal. No statistical difference in the incidence of such anomalies was observed between the controls and the intoxicated animals.

Hydrofluorosis in water buffalo (Bubalus bubalis) in India.

The concentration of fluoride was determined in water, forage and urine and serum samples of buffaloes from the Unnao district of India. The water and forage samples contained 2.01 +/- 0.51 and 22.50 +/- 0.82 ppm of fluoride, respectively. The analysis of biosamples collected from the affected animals revealed higher levels of fluoride in serum (0.58 +/- 0.05 ppm) and urine (10.64 +/- 1.23 ppm). Clinical examination identified a 40.34% prevalence rate of clinical lesions suggestive of fluorosis in buffalo of this locality. Dental lesions were present invariably in all affected animals whereas lameness, painful bony exostosis and emaciation were recorded in 28.17%, 8.45% and 76.00% of the animals. Based on the clinical lesions and fluoride content in water, serum and urine, it was concluded that the problem of fluorosis in buffalo is attributable to drinking water containing toxic levels of fluoride.

A field study of the validity of static paper sampling in fluoride pollution surveys.

A field study of fluoride pollution and of its consequences was made over a period of five years in the vicinity of an alumina reduction plant. This study, based upon the use of a static soda impregnated paper sampler, shows that the results obtained are in good agreement with the atmospheric fluoride concentrations obtained with dynamic samplers, especially when fluoride is present in gaseous form (HF). The results suggest that vertically mounted paper samplers are less sensitive to the collection of particulate fluorides. Collection rate is strongly influenced and increases with speed. If this parameter is known, an accurate estimation of the absolute atmospheric concentration is possible; the values shown by this technique are in good correlation with the value (annual mean) of pasture fluoride content. As a correlation exists between pasture fluoride content and the symptoms shown by cattle, the static filter samplers can predict disease in the case of slow chronic fluorosis. The field study agrees with earlier laboratory experiments and shows the validity of these simple and inexpensive types of exposure methods.

Industrial fluorosis in cattle and buffalo around Udaipur, India.

Signs of dental discolouration, difficulty in mastication, bony lesions, lameness, debility and mortality in domesticated animals, reared around superphosphate fertiliser plants located approximately 15 km north of Udaipur, Rajasthan prompted us to investigate for the occurrence of fluorosis. Out of 166 animals clinically examined, the prevalence rate was 17.4% (4/23) in calves below 1 year of age, 37.2% (16/43) in cattle between 1 and 3 years, 61.3% (46/75) in cattle above 3 years and 72% (18/25) in buffalo above 1 year. Dental fluorosis was common in buffalo compared to cattle of all the age groups. Fluoride levels in fodder and water, consumed by the animals were much higher than the recommended permissible limit. Mean fluoride concentrations in serum and urine were 1.53 +/- 1.27 and 26.4 +/- 6.17 mg l(-1) in calves below 1 year of age, 0.56 +/- 0.17 and 26.2 +/- 3.86 mg l(-1) in cattle of 1-3 years, 0.49 +/- 1.13 and 27.5 +/- 4.63 mg l(-1) in cattle above 3 years and 0.60 +/- 0.07 and 28.6 +/- 4.73 mg l(-1) in buffalo over 1 year, respectively. The values were significantly (P < 0.01) higher than those of control animals kept over a 15-km distance from the factories. Fluoride concentrations in the environmental sample collected from the affected locality were 534.4 +/- 74.9 mg kg(-1) in fodder, 1.19 +/- 0.29 mg l(-1) in pond water and 0.479 +/- 0.351 mg l(-1) in tube well water. It was concluded that the consumption of fodder and water contaminated by the fumes and dusts emitting from superphosphate fertiliser plants resulted in the development of chronic fluorotic lesions in cattle and buffalo.

A quantitative backscattered electron imaging study of hypomineralization and hypoplasia in fluorosed dental enamel of deer.

Mineral content and distribution of fluorosed and unfluorosed (control) dental enamel of roe deer and red deer cheek teeth were analyzed using digital backscattered electron (BSE) imaging of PMMA-embedded specimens. Compared to the controls, the fluorosed enamel exhibited various aberrations resulting from a fluoride-induced disturbance of the processes involved in enamel formation. Thus, the presence of surface hypoplasias and an enhancement of the incremental pattern in the fluorosed enamel are evidence of a fluoride impact on the secretory ameloblasts, whereas a (subsurface) hypomineralization of different depth and extent is indicative of a fluoride effect on the maturation stage of amelogenesis. The marked variation in the severity of enamel hypomineralization seen along the coronocervical axis of a specimen pointed to a fluoride impact of varying intensity during this period of tooth development. Our observations further indicated that, in some locations, ameloblasts severely affected by fluoride during enamel matrix formation were able to recover from this insult and to function quite normally during the maturation stage of amelogenesis. A major advantage of the BSE imaging technique used in the present study over other methods is that it allows for a combination of micromorphological information with quantitative data on the mineralization of the analyzed tissue, which proved to be very useful for the characterization of fluoride-induced changes in dental enamel.

Relationship of cheek tooth abrasion to fluoride-induced permanent incisor lesions in livestock.

Teeth from cattle, sheep, and horses that ingested various fluoride intakes and teeth from field studies of these species plus deer, elk, and bison were examined for abnormalities. Approximately 99,000 animals in 322 herds were examined for fluorosis. From field studies, 988 cattle of various ages and with different degrees of dental fluorosis were slaughtered and necropsied. The severity of fluoride-induced mottling, hypoplasia, and abnormal abrasion of paired permanent incisor teeth was correlated with abrasion of premolar and molar (cheek) teeth that form and mineralize at approximately the same age. Severe irregular wear of cheek teeth impaired mastication and resulted in poor utilization of feed and unthriftiness. Excessive amounts of fluoride during tooth formation and mineralization induce characteristic dental changes. Offspring from the fluoride-affected animals did not have discernible fluoride-induced lesions in the deciduous teeth.

Fluorosis in black-tailed deer.

Marked dental disfigurement and abnormal tooth wear patterns were observed in black-tailed deer (Odocoileus hemionus columbianus) taken from an area near an industrial fluoride source in northwestern Washington. Fluoride levels in the bones of these deer were from 10 to 35 times higher than levels in the bones of normal animals. These levels are similar to those associated with fluorosis of cattle.

Effects of fluoride emissions from a modern primary aluminum smelter on a local population of white-tailed deer (Odocoileus virginianus).

The influence of fluoride emissions from a modern aluminum smelter on concentrations of skeletal fluoride and dental fluorosis in a resident population of white-tailed deer was studied. The smelter was located on Mount Holly Plantation in South Carolina, and concentrations of skeletal fluoride in the deer collected at Mount Holly increased approximately five-fold 3 yr after the operation began. Increases in skeletal fluoride of less than two-fold were observed in deer obtained from Medway Plantation which has its nearest boundary 1.6 km from the smelter site. No dental fluorosis was observed in deer collected at Medway Plantation, but mild dental fluorosis was observed in a significant number of deer collected at Mount Holly Plantation. The dental fluorosis that was observed was not associated with incisor wear or with fluoride-induced molar wear. Osteofluorosis of mandibles or metacarpals was not observed in any of the deer obtained from either plantation. The data obtained from this study indicated that the presence of a modern aluminum smelter caused a detectable increase in concentration of skeletal fluoride in the resident population of white-tailed deer, but that no adverse health effects were seen.

Bone fluoride concentrations in beluga whales from Canada.

Beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary have been reported to have dental and bone abnormalities. To determine whether these lesions could be caused by high exposure to fluorides, we measured bone fluoride levels in eight beluga whales stranded on the shores of the St. Lawrence Estuary (Quebec, Canada), and in nine beluga whales killed by Inuit hunters in the Hudson Bay (North Western Territories, Canada). In both groups, fluoride concentrations were higher than those found in terrestrial mammals intoxicated by fluorides. Unexpectedly, fluoride concentration was significantly higher in beluga whales from the Hudson Bay (mean +/- SD: 10.365 +/- 1.098 ppm) than in beluga whales from the St. Lawrence Estuary (4.539 +/- 875 ppm) and was positively correlated with age in the latter population. Differences in diet might explain the differences in fluoride concentrations found between these two populations.

Fluoride toxicosis in wild ungulates.

To compare the occurrence of chronic fluoride toxicosis in wild and domestic animals in selected areas of Utah, Idaho, Montana, and Wyoming, deer, elk, and bison bones and teeth were collected for evaluation. Vegetation and drinking water samples also were collected, so that potential sources of fluoride could be evaluated. Deer, elk, and bison were found to be susceptible to the adverse effects of ingestion of excessive amounts of fluoride. Teeth and bones were primarily affected with characteristic lesions. Pathognomonic soft tissue changes were not observed. The animals had been exposed to a variety of sources of excessive fluoride, including water high in fluoride, forages contaminated by industrial effluents that were high in fluoride, vegetation contaminated with high fluoride-content soil by rain splash or wind, or a combination of these sources. Waters high in fluoride, especially from geothermal springs and wells, often contained appreciable amounts of various soluble salts. Evidence accumulated from specimens collected throughout the aforementioned states indicated that there are areas where chronic fluoride toxicosis is a problem for wildlife. These areas were where natural sources of fluorine (especially geothermal waters) provided amounts for ingestion that exceed species tolerance limits or were near certain industrial operations.

Alleviation of fluorine toxicity in starting turkeys and chicks with aluminum.

Aluminum (Al) compounds were evaluated as fluorine (F) toxicity alleviators in starting broiler chicks and turkeys. Added F levels from NaF ranged from 0 to 1000 ppm, whereas Al levels varied from 0 to 800 ppm. Al was fed either as Al2O3 or Al2 (SO4)3.18H2O. When fed as the sulphate salt, 800 ppm of Al completely prevented the toxic effect of at least 1000 ppm of F. Al2O3 was not effective as an alleviator of fluorine toxicity. When the mode of action of Al2(SO4)3.18H2O against F toxicity was studied in colostomized turkeys it was apparent that F absorption occurred but was probably less efficient than previously reported in ruminants. Al significantly (P less than .05) reduced F absorption in turkeys. Urinary F levels were: 2.4 ppm in birds fed a control diet (26 ppm F), 17.8 ppm in birds fed a diet with 1000 ppm F, and 6.7 ppm in birds fed the high F diet with 800 ppm Al as the sulphate salt. In addition, data from this study indicated that starting broiler chicks were more tolerant (800 ppm F) than starting turkeys (600 ppm F) to fluorine toxicosis.

Fluorosis in dairy cattle.

The investigation of a high incidence of arthritis in 21 dairy herds disclosed elevated fluorine levels in bone samples. In every herd except one, where herbage and water was contaminated by industrial fall-out, the main source of the fluorine was from mineral supplements; In a few herds, purchased cake or grain balancers contributed to the abnormal levels. Over 100 cows with arthritis had fluroine levels in the bone of between 2000 and 8000 ppm, or were in herds whose diet contained excess fluorine. Characteristic tooth lesions often confirmed the link between arthritis and fluorosis. Sixteen out of 31 samples of mineral supplement contained dangerous levels of fluorine (3000 to 13000 ppm). Grain balancers contained up to 400 ppm F, and dairy cake had levels as high as 140 ppm F. There was a statistical correlation between a high incidence of damage to peri-articular structures, resulting in debility and loss of production, and elevated bone fluorine.

Evaluating a fluorosis hazard after a volcanic eruption.

The August, 1991 eruption of Mt. Hudson (Chile) deposited ash across southern Argentina and contributed to the deaths of thousands of grazing sheep. Early ash analysis revealed high levels of fluoride, a potential ash constituent toxic to humans and animals. In order to evaluate fluorosis as the cause of sheep deaths and to examine the possibility that similar ash and airborne toxins could also have an effect on the human population, we conducted an investigation that included health provider interviews, hospital record review, physical examination of sheep, determination of sheep urine fluoride levels, and complete constituent analysis of ash samples collected at proscribed distances from the volcano. Ash deposited farthest from the volcano had highest fluoride levels; all fluoride measurements were normal after rainfall. There were no signs or symptoms of fluorosis observed in sheep or humans. Sheep deaths resulted from physical, rather than chemical properties of the ash.

Phosphorus supplements and fluorosis in cattle--a northern Australian experience.

Chronic fluoride toxicosis caused lameness, dental lesions and illthrift in an extensive beef cattle herd in northern Australia. Up to 15% of the herd was lame and the disease forced the culling of large numbers of cows. The source of fluoride was fertiliser-grade monoammonium and diammonium phosphate fed as part of a mineral supplement. Large quantities of mineral supplement were provided to the cattle because lameness was attributed to phosphorus deficiency, which is endemic in the area. Most lameness developed in the late dry season in the post-lactation phase. Severe lameness was caused by fractured pedal bones.

Chronic gypsum fertiliser ingestion as a significant contributor to a multifactorial cattle mortality.

OBJECTIVE: To assess the validity of claims that heavy metal contamination from an open-cut mine caused the death of 226 cattle on a nearby farm over a period of 18 months, and to investigate other possible contributing factors. PROCEDURE: A retrospective assessment of previous investigations combined with additional chemical analyses. RESULTS: Extensive chemical analyses produced no evidence of heavy metal contamination associated with the mine. Analysis of bones indicated exposure to fluoride in greater than normal amounts. The main source of fluoride seems to have been gypsum that was included in a feed supplement and also ingested from fertiliser dumps on paddocks. The gypsum itself may have contributed significantly to the ill health. Other factors probably affected some classes of animals, notably the young calves. CONCLUSIONS: What originally seemed to be a disease problem of single aetiology probably was an expression of interacting multifactorial causes. This investigation has highlighted the potential toxicity of gypsum to livestock and the need for further studies to establish its basis.

Chronic fluoride poisoning in sheep.

Chronic fluoride poisoning in sheep and cattle was diagnosed on a farm in the Vredenburg district, Cape Province, and confirmed by laboratory analysis. The source of the poisoning was pastures contaminated with rock phosphate dust containing 2,1 to 3,3% of fluoride emitted from a fertilizer factory. Tabulated analyses of blood, liver, bone, pasture and water are given.